4. Ability to become pregnant (or already pregnant or lactating). However, those female patients who have a negative serum or urine pregnancy test before enrolment and agree to use two highly effective forms of contraception (oral, injected or implanted hormonal contraception and condom, have a intra-uterine device and condom, diaphragm with spermicidal gel and condom) during the study and for six months afterwards are considered eligible.